Control apparatus



O. P. SCHUSTER CONTROL APPARATUS June 16, 1925. 1,541,857

Filed Aug. 12. l922 INVENTOR 0/70RSd7us7er mTdRm Y Patented June 16,1925.

UNITED STATES ENT orrics;

ortro nsonusrnn, or woman Inwin, rnnnsirnvania. assisnon To WESTINGHOUSEELECTRIC & MANUFACTURING COMPANY, a CORPORATION or rnmv'sYLvAnIA.

coarser APPARATUS.

Application area August 12, r922. Serial No. 551,321

ani'sms and it has particular relation to switches of the contactortype, commonly employed in the controi "of electric motors and the like.

Anobj'ect of my invention is to provide 15 means :toradjus'ting therelative positions of the switch COiiiitCtIIieiflbGIS so as to insureproper alinement.

Another object of m invention is to provide means for compensating for areduction in contact pressure resulting from contact wear.

I am aware of the fact that is common practice to provide some meansforadjus'ti-ng switch contact members. However, the

majority of such devices are not con-iiple'tely etlective.

My invention provides For three inclependent adjustments whereby thecontact members, when in normal eng; gement, are

* always in perfect alinement.

My invention will be described in connection with the accompanyingdrawing, in which Figure 1 is a view. partially in elevation andpartially in section, of a switch mechanism embodying my invention,

Fig. 2 is a view of a portion of the movable contact switch member shownin Fig.

1, and

F 3 is a view of a portion of the stationary contact member illustratedin Fig. 1.

Referring particularly to Fig. 1, a stationary contact member 1 issecured to aholding member 22 having a serrated surface, by means of abolt 2*. A. supporting member or bracket 3 also provided with acorresponding serrated surface, the two serrated surfaces cooperatin cfor purposes of adjustment, as subsequently explained. A movable contactmember a is mounted upon an adjustable member 5 and a rocker member 6,both of the latter being provided with cooperating serrated surfaces andbeing held in engagement by means of bolt 7.

The rocker member 6 is provided with a shaft 8, which is carried byalever arm 9 that is pivotally mounted upon a bracket 11. The bracket 11sup-ports a contact spring 12 oi a familiar character and is mountedupon, and suitably insulated from, a stationary supporting bar or shaft13.

For convenience, I have illustrated a switch of the cam-operated type,although it is evident that the switch may be operatedele'ctromagnetioally or otherwise. I have shown the outline of a camsuitable for engaging with a roller 14: that is mounted upon the lever9, for actuating the movable contact member 4.

The switch contact members are illustrated in closed position. positionof the contact member 4 indicates the inoperative or open position oithe switch. The stationary holding member 2 is slotted as shown in 3,for the purpose of receiving; the bolt 2, and it is evident that anydesirable adjustment o-t', the contact member 1 may be made along thedirection of the slotted portion of the holding member 2.

The rocker member '6, il lustrated in Fig. 2,

is similarly slotted, for the purpose or receiving the bolt 7, wherebythe movable 'contact member 1 may be moved toward or away from thecontact member 1, without altering the position of the lever By shiftingthe position oi the member 5 along the serrated surface of the member 6,the ultimate compression or length of the spring 12 may correspondinglyvary, the member 6, of course, rotatingabout the shaft 8. Lateralalinement or movement of con tact member 4t is effected, in a planeperpendicular to the plane of the drawing, by shifting the bracket 11along the insulated shaft 13, a clamping member 15 with bolts 16 and 17being provided for this purpose. The switch is illustrated in perfectaline ment, but it will be evident, to those skilled in the art, thatvariations in manufacture ordinarily prevent such exact alinement. It isfor this purpose that the adjustments described above have beenprovided. In the operation of a switch of this character, the tip of themoving contact member 4, during the closing movement of the switch,first engages the tip of the stationary contact member 1, by reason ofthe biasing action of the spring 12. These tips are represented at theextreme right hand portions The dotted line of the contact members, asillustrated. As the switch is actuated to its fully closed position, thecontact member 4 rolls along the surface of the stationary member 1until the heels or lower left hand portions of the contact members arein alinement, as represented by the line 18.

In service, the natural wear of the contact members results in a loss ofcontact pressure and a corresponding decrease in the current-carryingcapacity of the switch. As the switch members wear, the rocker member 6,in the closing movement of the switch, has less of an angular movementabout the shaft 8 in a counter-clockwise direction, and consequentlythere is less compression upon the contact spring 12. Normal contactpressure is restored by moving the adjustable member 5 downward to theextent of one or more teeth of the serrated surface, so that in theclosed position of the switch, a straight line, as 18, is maintainedalong the heels of the contact memhers.

I have illustrated my invention in a particular form, viz, as applied toa switch of the well-known contactor type. I believe, however, that myinvention will readily lend itself to other applications, and I,therefore, do not Wish to be restricted to devices solely of thecharacter described.

I claim as my invention:

1. A switch comprising stationary and movable contact members, saidmembers being independently adjustable to effect relative alinement, aspring for rotating the movable member, and means compensating fordecrease in contact pressure resulting from wear.

2. A switch comprising stationary and movable contact members, saidmembers being adjustably mounted on serrated surfaces to effectrelativecontact alinement, a spring for rotating the movable member, andmeans for maintaining normal contact pressure.

3. A switch comprising a stationary member adjustable along a givenline, a co-opcrating movable member, means for adjusting its movement inthe direction of its norcontact member, for engaging with said sta-.

tionary member, means for rotating said movable member, an insulatedshaft for supporting the movable member and means for adjusting therelative positions of said contact members in planes perpendicular toone another.

5. A switch comprising a movable contact member having a serratedsurface and a similarly surfaced rotatable supporting member, of anoperating lever for mounting the supporting member, a bearing bracketfor said lever, an insulated shaft for supporting the bearing bracket, astationary contact member and a supporting bracket therefor, each havingco-operating serrated surfaces in mutual engagement, means for adjustingsaid members from tooth to tooth along said serrated surfaces and meansfor maintaining said bearing bracket in alinement with said contactmembers.

In testimony whereof, I have hereunto subscribed my name this 8th day ofAugust, 1922.

OTTO P. SCI-IUSTEH.

